Machines such as dozers and motor graders are used to perform a variety of tasks including moving, digging, loosening and carrying different materials at a worksite. For example, these machines may include ground engaging implements used to engage a work surface to move material and/or otherwise alter the work surface at a work site. The machines may operate in an autonomous, semi-autonomous, or manual manner to perform these tasks in response to commands that may be generated as part of a work plan for the machines.
When operating a machine to move material according to a material movement plan, under some circumstances, the machine may not be able to efficiently move the desired material according to the plan. The ground or work surface may range from loose soil that may be moved relatively easily to compacted material or material with embedded rocks and other items that are more difficult to move efficiently. As a result, as a machine traverses a work site, it may encounter varying work surface conditions. Upon engaging an area with a relatively hard work surface, the machine may be subjected to excessive wear and move along the work surface without moving a significant amount of material. In such case, it may be desirable to utilize a ripper mechanism to break-up or dislodge the hard material to reduce wear on the machine and so that the machine may move the material in an efficient manner.
Autonomous or semi-autonomous movement of machines is increasingly desirable for many operations including those related to mining, earthmoving and other industrial activities. Autonomously operated machines may remain consistently productive without regard to a human operator or environmental conditions. In addition, autonomous systems may permit operation in environments that are unsuitable or undesirable for a human operator. However, tasks that typically rely upon the judgment of an experienced operator, such as determining when to engage a ripper mechanism, are generally more challenging to perform in an autonomous or semi-autonomous manner.
U.S. Patent Publication No. 2010/0299031 discloses a system for controlling an earthmoving machine in which resistance force vectors of soil resistance to cutting and dragging may be determined and used as input to the control system. The resistance force vector may depend on the volume, weight and condition of the material in front of the blade.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.